[0001] The present invention relates to gas venting. In particular, but not exclusively,
the present invention relates to the venting of gas from a flexible pipe, including
flexible pipe body and one or more end fittings, and also to the end fitting and the
flexible pipe itself. The venting helps to prevent the build-up of gases that have
permeated into the flexible pipe body from fluids such as oil or gas being transported,
and helps to reduce the risk of collapse of the flexible pipe body. Certain embodiments
of the present invention relate to a vent arrangement for venting the annulus of a
flexible pipe that reduces the risk of vent blockage. Certain embodiments further
provide for flushing a vent valve and the connection of the vent valve to the annulus.
[0002] Traditionally flexible pipe is utilised to transport production fluids, such as oil
and/or gas and/or water, from one location to another. Flexible pipe is particularly
useful in connecting a sub-sea location (which may be deep underwater) to a sea level
location. The pipe may have an internal diameter of typically up to around 0.6 metres
(e.g., diameters may range from 0.05 m up to 0.6 m). Flexible pipe is generally formed
as an assembly of a flexible pipe body and one or more end fittings. The pipe body
is typically formed as a combination of layered materials that form a pressure-containing
conduit. The pipe structure allows large deflections without causing bending stresses
that impair the pipe's functionality over its lifetime. The pipe body is generally
built up as a combined structure including polymer, and/or metallic, and/or composite
layers. For example, a pipe body may include polymer and metal layers, or polymer
and composite layers, or polymer, metal and composite layers. Some of these layers
may be bonded to one another, for instance a composite pressure armour layer may be
bonded, through physical or chemical means, to a polymer barrier layer. This bonding
of these layers may be possible, for instance, as a result of the composite comprising
material of sufficient similarity to that of the polymer barrier layer that it may
readily be joined through for example the application of heat and pressure, or the
materials may be sufficiently dissimilar to require an intermediate tie-in layer of
a suitable material (see also application
GB1402264.4).
[0003] In many known flexible pipe designs the pipe body includes one or more pressure armour
layer. The primary load on such layers is formed from radial forces. If the pressure
armour layers comprise one or more tape or wire, these often have a specific cross
section profile to interlock so as to be able to maintain and absorb radial forces
resulting from outer or inner pressure on the pipe. The cross sectional profile of
the wound wires which thus prevent the pipe from collapsing or bursting as a result
of pressure are sometimes called pressure-resistant profiles. When pressure armour
layers are formed from helically wound wires forming hoop components, the radial forces
from outer or inner pressure on the pipe cause the hoop components to expand or contract,
putting a tensile load on the wires. Similarly these radial forces may be resisted
by a continuous layer of composite material applied in known ways to the pipe in place
of pressure armour wires or tapes.
[0004] In many known flexible pipe designs the pipe body includes one or more tensile armour
layers. The primary loading on such a layer is tension. In high pressure applications,
such as in deep and ultra-deep water environments, the tensile armour layer experiences
high tension loads from a combination of the internal pressure end cap load and the
self-supported weight of the flexible pipe. This can cause failure in the flexible
pipe since such conditions are experienced over prolonged periods of time, particularly
in dynamically loaded pipes, where fatigue damage can accumulate in the elements which
make up the tensile armour layers (for example wires or tapes).
[0005] Unbonded flexible pipe has been used for deep water (less than 3,300 feet (1,005.84
metres)) and ultra-deep water (greater than 3,300 feet) developments. It is the increasing
demand for oil which is causing exploration to occur at greater and greater depths
where environmental factors are more extreme. For example in such deep and ultra-deep
water environments ocean floor temperature increases the risk of production fluids
cooling to a temperature that may lead to pipe blockage. Increased depths also increase
the pressure associated with the environment in which the flexible pipe must operate.
For example, a flexible pipe may be required to operate with external pressures ranging
from 0.1 MPa to 30 MPa acting on the pipe. Equally, transporting oil, gas or water
may well give rise to high pressures acting on the flexible pipe from within, for
example with internal pressures ranging from zero to 140 MPa from bore fluid acting
on the pipe. As a result the need for high levels of performance from the layers of
the flexible pipe body is increased. Flexible pipe may also be used for shallow water
applications (for example less than around 500 metres depth) or even for shore (overland)
applications.
[0006] Typically, metallic structural components such as pressure armour and tensile armour
layers are sandwiched between inner and outer barrier layers (alternatively referred
to as a liner and an outer sheath), for instance formed from a polymer that is impermeable
to liquids. Between the inner and outer barrier layers is a pipe annulus within which
is located the armour layers. While preferably the annulus is a sealed environment,
it is possible that liquid may ingress the annulus due to damage to the flexible pipe
body, and gas may also build up within the annulus. It is known to vent the annulus
to militate against the risk of a dangerous build-up of pressure within the annulus,
which in the extreme could result in a catastrophic failure of the flexible pipe body.
[0007] The end fittings of a flexible pipe may be used for connecting segments of flexible
pipe body together or for connecting them to terminal equipment such as a rigid sub-sea
structures or floating facilities. As such, amongst other varied uses, flexible pipe
can be used to provide a riser assembly for transporting fluids from a sub-sea flow
line to a floating structure. In such a riser assembly a first segment of flexible
pipe may be connected to one or more further segments of flexible pipe. Each segment
of flexible pipe includes at least one end fitting.
[0008] An end fitting may suitably be further configured to allow access to the pipe body
annulus. This may include coupling a vent valve to the annulus to prevent pressure
build-up. Generally, the flexible pipe and the end fitting include specific features,
for instance a vent pathway, which allows gases that have built up in the annulus
to be exhausted. A known problem is that if a vent valve or the coupling between the
vent valve and the annulus becomes blocked then pressure can begin to mount within
the annulus. It will be appreciated that due to mechanical motion of the flexible
pipe, friction within the armour layers may lead to debris build up within the annulus
as components bear against one another. Debris may also enter the annulus as a result
of a breach of a barrier layer. It has been observed, during dissections of vent valves
that have been in service, that vent valves coupled to the annulus of a flexible pipe
may be partially or completely blocked due to debris originating within the annulus.
Blocking is frequently experienced due to the small bore diameter of vent valves.
A known mitigation is to provide more than one vent valve independently coupled to
the annulus, though it will be appreciated that this increases the cost associated
with annulus venting. Furthermore, space within and around the end fitting for providing
multiple connecting pathways coupling to the annulus may be at a premium. Typically
a maximum of three access ports are provided per end fitting for coupling vent valves
to the pipe body annulus. It will be appreciated that if all three vent valves were
to become blocked then the pipe body could no longer be used, if no option for replacing
a vent valve is provided. Similarly, if a connecting tube between the pipe body annulus
and a vent valve were to become blocked then there may be no alternative but to remove
the vent valve and connect a hose for flushing the connecting tube and the annulus,
which may not be practicable for sub-sea locations. Alternatively, if a vent valve
is to be replaced this risks contaminants such as sea water entering the pipe body
annulus.
[0009] WO-2011/026801-A1 discloses a method of protecting a flexible pipe from corrosion comprising: (a) providing
a flexible pipe comprising: an outer sheath; an inner - an annular volume bounded
by the outer sheath and the inner sheath and comprising at least one metallic reinforcing
layer and a dry annular void; a pipe fluid passage, located within the inner sheath;
a first end having a first end-fitting comprising a first port in fluid communication
with the pipe fluid passage, and at least one protective liquid injection port in
fluid communication with the annular void; a second end, having a second end-fitting
comprising a second port in fluid communication with the pipe fluid passage, and at
least one fluid release valve in fluid communication with the dry annular void; and
(b) passing a protective liquid to the protective liquid injection port of the first
end-fitting, thereby filling the dry annular void within the annular volume with protective
liquid to provide a protected flexible pipe.
[0010] WO-2012/092931-A1 discloses an unbonded flexible pipe for subsea transportation of fluids. The pipe
has a length and comprises a tubular inner sealing sheath defining a bore and an axis
of the pipe. In a pipe length section it comprises a second sealing sheath surrounding
the inner sealing sheath and forming an annulus between the inner sealing sheath and
the second sealing sheath. The annulus provides a primary maintaining passage along
the length of the pipe length section with a first and a second end. The pipe comprises
at least one secondary maintaining passage along the length of the pipe with a first
and a second end. The secondary maintaining passage is arranged with an axial distance
which is larger than the axial distance of the inner sealing sheath. The first end
of one of the primary and the secondary maintaining passages is arranged as an input
end for a maintaining fluid and the first end of the other of the primary and the
secondary maintaining passages is arranged as an outflow end for the maintaining fluid,
and the primary and the secondary maintaining passages are in fluidic connection with
each other at their second ends to provide a pathway for the maintaining fluid. The
pathway for a maintaining fluid makes it possible in a simple and effective manner
to keep the corrosion of elements - such as armouring elements in the annulus - relatively
low, and accordingly the duration of the unbonded flexible pipe can thereby be increased.
[0011] US-2008/149209-A1 discloses a method for the drainage of permeate gases from a flexible tubular pipe.
The pipe comprises at least one inner pressure sleeve, for the transport of hydrocarbons,
which contain permeate gases which diffuse across the wall of the inner pressure sleeve.
The pipe has an outer sleeve and several reinforcement layers, arranged in an annular
zone between the outer sleeve and the inner pressure sleeve. The annular zone has
transport ducts in which the permeate gases can circulate towards the removal. The
method comprises a forced circulation of the permeate gases in the annular zone through
the transport ducts towards the removal.
[0012] It is an aim of the present invention to at least partly mitigate the above-mentioned
problems.
[0013] It is an aim of embodiments of the present invention to provide an arrangement in
which flexible pipe body is less likely to be subjected to excess pressure by gas
build-up resulting from blocking of a venting arrangement.
[0014] According to a first aspect of the present invention there is provided a vent arrangement
for a flexible pipe body according to claim 1.
[0015] According to a second aspect of the present invention there is provided an end fitting
for a flexible pipe body according to claim 7.
[0016] According to a third aspect of the present invention there is provided a flexible
pipe according to claim 9.
[0017] According to a fourth aspect of the present invention there is provided a method
of manufacturing a flexible pipe according to claim 10.
[0018] Certain embodiments of the invention provide the advantage that the risk of a venting
arrangement being blocked is reduced. Certain embodiments of the present invention
provide a methodology and apparatus for reducing the development of pressure in annular
regions of a flexible pipe by allowing gas to be vented from the annular regions of
a flexible pipe body.
[0019] Embodiments of the invention are further described hereinafter with reference to
the accompanying drawings, in which:
Fig. 1 illustrates the constructions of a flexible pipe body;
Fig. 2 illustrates a riser assembly suitable for transporting production fluid such
as oil and/or gas and/or water from a sub-sea location to a floating facility;
Fig. 3 illustrates an end fitting of a flexible pipe;
Fig. 4 illustrates an enlarged portion of part of Fig. 3;
Fig. 5 illustrates an enlarged portion of part of Fig. 3;
Fig. 6 illustrates an enlarged portion of part of Fig. 3;
Fig. 7 illustrates an enlarged portion of part of Fig. 3;
Fig. 8 illustrates a vent arrangement for a flexible pipe body according to an embodiment
of the present invention; and
Fig. 9 illustrates a vent arrangement for a flexible pipe body according to another
embodiment of the present invention.
[0020] In the drawings like reference numerals refer to like parts.
[0021] Throughout this description, reference will be made to a flexible pipe. It will be
understood that a flexible pipe is an assembly of a portion of pipe body and one or
more end fittings in each of which a respective end of the pipe body is terminated.
Fig. 1 illustrates how pipe body 100 is formed in accordance with an embodiment of
the present invention from a combination of layered materials that form a pressure-containing
conduit. Although a number of particular layers are illustrated in Fig. 1, it is to
be understood that the present invention is broadly applicable to coaxial pipe body
structures including two or more layers manufactured from a variety of possible materials.
For example, the pipe body may be formed from polymer layers, metallic layers, composite
layers, or a combination of different materials. It is to be further noted that the
layer thicknesses are shown for illustrative purposes only. As used herein, the term
"composite" is used to broadly refer to a material that is formed from two or more
different materials, for example a material formed from a matrix material and reinforcement
fibres or wires.
[0022] As illustrated in Fig. 1, a pipe body 100 includes an optional innermost carcass
layer 101. The carcass provides an interlocked construction that can be used as the
innermost layer to prevent, totally or partially, collapse of an internal pressure
sheath 102 due to pipe decompression, external pressure, and tensile armour pressure
and mechanical crushing loads. The carcass layer is often a metallic layer, formed
from stainless steel, for example. The carcass layer could also be formed from composite,
polymer, or other material, or a combination of materials. It will be appreciated
that certain embodiments of the present invention are applicable to 'smooth bore'
operations (i.e. without a carcass layer) as well as such 'rough bore' applications
(with a carcass layer).
[0023] The internal pressure sheath 102 acts as a fluid retaining layer and comprises a
polymer layer that ensures internal fluid integrity. It is to be understood that this
layer may itself comprise a number of sub-layers. It will be appreciated that when
the optional carcass layer is utilised the internal pressure sheath is often referred
to by those skilled in the art as a barrier layer. In operation without such a carcass
(so-called smooth bore operation) the internal pressure sheath may be referred to
as a liner.
[0024] An optional pressure armour layer 103 is a structural layer that increases the resistance
of the flexible pipe to internal and external pressure and mechanical crushing loads.
The layer also structurally supports the internal pressure sheath, and typically may
be formed from an interlocked construction of wires wound with a lay angle close to
90°. The pressure armour layer is often a metallic layer, formed from carbon steel,
for example. The pressure armour layer could also be formed from composite, polymer,
or other material, or a combination of materials.
[0025] The flexible pipe body also includes an optional first tensile armour layer 105 and
optional second tensile armour layer 106. Each tensile armour layer is used to sustain
tensile loads and internal pressure. The tensile armour layer is often formed from
a plurality of wires (to impart strength to the layer) that are located over an inner
layer and are helically wound along the length of the pipe at a lay angle typically
between about 10° to 55°. The tensile armour layers are often counter-wound in pairs
to balance twist or torque in the pipe when these layers are put under tension. The
tensile armour layers are often metallic layers, formed from carbon steel, for example.
The tensile armour layers could also be formed from composite, polymer, or other material,
or a combination of materials.
[0026] The flexible pipe body shown also includes optional layers of tape 104 which help
contain underlying layers and to some extent prevent abrasion between adjacent layers.
The tape layer may be a polymer or composite or a combination of materials.
[0027] The flexible pipe body also typically includes optional layers of insulation 107
and an outer sheath 108, which comprises a polymer layer used to protect the pipe
against penetration of seawater and other external environments, corrosion, abrasion
and mechanical damage.
[0028] For the flexible pipe body 100 shown in Fig. 1, the pipe body annulus extends between
the internal pressure sheath 102 and the outer sheath 108.
[0029] Each flexible pipe comprises at least one portion, sometimes referred to as a segment
or section of pipe body 100 together with an end fitting located at one end or both
ends of the flexible pipe. An end fitting provides a mechanical device which forms
the transition between the flexible pipe body and a connector. The different pipe
layers as shown, for example, in Fig. 1 are terminated in the end fitting in such
a way as to transfer the load between the flexible pipe and the connector.
[0030] Fig. 2 illustrates a riser assembly 200 suitable for transporting production fluid
such as oil and/or gas and/or water from a sub-sea location 201 to a floating facility.
For example, in Fig. 2 the sub-sea location 201 includes a sub-sea flow line. The
flexible flow line 205 comprises a flexible pipe, wholly or in part, resting on the
sea floor 204 or buried below the sea floor and used in a static application. The
floating facility may be provided by a platform and/or buoy or, as illustrated in
Fig. 2, a ship 200. The riser assembly 200 is provided as a flexible riser, that is
to say a flexible pipe 203 connecting the ship to the sea floor installation. The
flexible pipe may be in segments of flexible pipe body with connecting end fittings.
[0031] It will be appreciated that there are different types of riser, as is well-known
by those skilled in the art. Embodiments of the present invention may be used with
any type of riser, such as a freely suspended (free, catenary riser), a riser restrained
to some extent (buoys, chains), totally restrained riser or enclosed in a tube (I
or J tubes).
[0032] Fig. 2 also illustrates how portions of flexible pipe can be utilised as a flow line
205 or jumper 206.
[0033] Fig. 3 illustrates how an end of a segment of flexible pipe body 100 may be terminated
in an end fitting 300. While one particular form of end fitting 300 is described in
detail in order to illustrate how conventionally a venting arrangement serves to exhaust
gases from a pipe body annular region, it will be understood that the present invention
is not limited to the particular form of end fitting shown here, especially in relation
to matters separate to gas venting.
[0034] The end fitting 300 includes a generally annular body 301, which has an axially extending
inner bore 302. The end fitting body is made from steel or other such rigid material.
The inner bore 302 has a diameter that preferably matches a corresponding inner diameter
of the segment of flexible pipe body to be terminated in the end fitting 300. In use,
production fluid can flow smoothly through the inner bore of the flexible pipe body
and the inner bore 302 of the end fitting. The end fitting body 301 at a first end
thereof defines an open mouth region in which a suitably cut end of flexible pipe
body may be introduced during a termination process. A flange region 303 extends outwardly
from the end fitting body 301 and is located near a remaining end region of the end
fitting body. The flange region forms a connector for connecting the end fitting to
a matching connector of a further end fitting of an adjacent segment of flexible pipe,
or to a floating or stationery structure or vessel for example. An end fitting jacket
304 is secured to the flange region 303 by a suitable securing mechanism such as one
or more bolts 305. The jacket 304 houses various components of the end fitting and
helps to protect them.
[0035] The flexible pipe body 100 is a multi-layered structure, for example as per Fig.
1, comprising at least a carcass layer 101, barrier layer 102 and outer sheath 108.
In this embodiment the flexible pipe body also includes a seal layer 109 of polymer
provided around a pressure armour layer 103. The various layers of flexible pipe body
are cut at desired lengths prior to termination in the end fitting 300.
[0036] The flexible pipe body is brought together with the open mouth region of the end
fitting body 301. The open mouth region has a stepped region 305 to receive a sealing
ring 306
1, and then the carcass layer 101 and barrier layer 102. The sealing ring 306
1 helps to seal the ends of the carcass layer and barrier layer.
[0037] A further sealing element 306
2 is located in a generally tapered recess formed between an inner surface of the open
mouth region and a radially outer surface of the barrier layer 102. The sealing element
306
2 is generally annular with a tapered edge to conform to the end fitting body, and
may be of polymer or metal or a mixture thereof, for example.
[0038] An inner collar 307 is secured to an end of the open mouth region of the end fitting.
During the termination process the securing of the inner collar 307 to the end fitting
300 will drive the sealing ring 306
2 into the tapered recess to provide a good seal. The inner collar 307 may be formed
from steel and may be substantially ring-like in shape. Further O-ring seals may be
provided to help provide a seal for preventing a leak path between the inner collar
307 and the end fitting, and the inner collar and an outer collar 308.
[0039] The outer collar 308 may be a Flexlok™ collar available from GE Oil & Gas UK Ltd.
The outer collar is provided radially outwards of a seal layer 109 and is secured
to the end fitting by one or more bolts, for example, via the inner collar 307. A
yet further sealing element 306
3 is located in a tapered recess between an inner surface of the outer collar 308 and
a radially outer surface of the seal layer 109. The seal ring 306
3 may be a Flexlok™ Ring available from GE Oil & Gas UK Ltd, for example.
[0040] Further layers of the flexible pipe body that lie radially outside the seal layer
109 are terminated at desired lengths within a cavity 309 defined between an inner
surface of the jacket 304, the end fitting body 301 and the seal layer 109. The cavity
309 may be filled with a resin material to help secure layers of flexible pipe body
to the end fitting. An outer sheath 108 is secured between a collar 310 and the end
fitting jacket 304.
[0041] It will be appreciated that the barrier layer 102 and the seal layer 109, which is
coaxial with the barrier layer 102, form between them an elongate pipe body annular
region. This annular region contains the pressure armour layer 103, but could include
further layers such as armour wires and tape layers depending on the flexible pipe
body design.
[0042] Similarly, the seal layer 109 and outer sheath 108, which is coaxial with the seal
layer 109, form between them a further elongate annular region. This further annular
region may contain the tensile armour layers. Again, this annular region could contain
other layers such as armour wires and tape layers depending on the flexible pipe body
design. It will be appreciated though that alternative flexible pipe body designs,
not illustrated, may including only a single annular region or three or more annular
regions. The present invention is not limited to any particular arrangement of annular
region, only that there is at least one within which gases may build-up and may be
vented. Venting for the particular flexible pipe body and end fitting of Fig. 3 will
now be described.
[0043] As mentioned above, when production fluid such as gas or liquids containing gas are
transported through a flexible pipe, over time gas can permeate through the fluid
retaining layer (barrier layer) and accumulate in one or more pipe body annular region.
With two annular regions, gas could firstly accumulate in the inner annular region,
before pressure builds and the gas migrates though the seal layer to the outer annular
region. Any build-up of pressure in an annular region is detrimental to the construction
of the flexible pipe body and could decrease lifetime or cause complete failure of
the flexible pipe.
[0044] In the present end fitting 300, a vent flow fluid communication path (or "vent path")
311 for venting an inner annular region 312 of the flexible pipe body is formed through
the end fitting 300 between the inner annular region 312 and an outer surface of the
end fitting 300. A passageway runs through the inner collar 307 and a further passageway
runs through the outer collar 308. These passageways are formed to link the inner
annular region 312 with a tubular conduit 313 provided in the cavity 309. The tubular
conduit 313 extends from the connection with the passageway in the outer collar to
a connection with a further passageway 314 in the flange region 303 of the end fitting.
An enlarged view of the vent path in the section identified as DETAIL D is shown in
Fig. 7.
[0045] The passageway 314 runs from the connection with the tubular conduit 313 in a direction
parallel to the pipe's longitudinal axis. It may then turn 90° towards an exit point
on the side of the end fitting, though it will be appreciated that the orientation
of the exit point may vary. An enlarged view of the vent path 311 in the section identified
as DETAIL B is shown in Fig. 5. The vent path 311 additionally includes a valve 315
(referred to herein as a vent valve) located in a recess 316 in the end fitting. The
term "vent valve" is to be interpreted broadly to encompass any valve arrangement
capable of admitting gas or liquid from the pipe body annulus. The valve 315 is a
non-return valve of a mechanical type that opens when a small pressure difference
is created across the vent valve. This pressure difference may be set at around 2
bar. Accumulated gas may vent by virtue of an internal pressure being higher than
a pressure downstream of the vent valve (i.e. after the vent valve in terms of gas
being exhausted from the annulus region to an exit point). The non-return valve 315
provided in the vent path helps prevent or inhibit gas from returning to the inner
annulus region from the end fitting.
[0046] The drawing on the left hand side of Fig. 3 shows a view of the end fitting 300 in
a section orthogonal to the view shown on the right hand side of Fig. 3. An enlarged
view of the vent path in the section identified as DETAIL C is shown in Fig. 6. As
can be seen from the drawing on the left hand side of Fig. 3, the end fitting of Fig.
3 actually includes three separate vent paths and hence vent valves 315 fluidly connected
to the inner annular region of the flexible pipe body. The provision of three vent
paths is for redundancy and helps to maintain the function of gas venting should there
be a blockage, for example. However, according to various embodiments of the present
invention a single vent path, specifically a single vent valve, or any number of vent
valves could equally be used.
[0047] Referring again to Fig. 3, a further vent flow fluid communication path (or "vent
path") 318 for venting an outer annulus region 319 of the flexible pipe body is formed
through the end fitting 300 between the outer annulus region 319 and an outer surface
of the end fitting 300. As noted above, for other pipe body structures there may only
be a single annular region and hence no need to provide a second or further vent path.
A passageway runs through the end fitting jacket 304 from an end region of the jacket
furthest from the flange region. The passageway runs radially outwards from the bore
region and then turns 90° to run parallel to the pipe's longitudinal axis. As can
be seen in Fig. 3, this passageway is actually formed by two passageways provided
at 90° that interconnect at a junction, with the redundant sections of the passageways
being blocked by plug members, or the like. Part way along the jacket 304, the passageway
emerges from the jacket and is connected to a tubular conduit 320 located in the cavity
309. The tubular conduit extends from the connection with the passageway in the jacket
to a connection with a further passageway 321 in the flange region 303 of the end
fitting. These passageways 318, 320, 321 link the outer annulus region 319 with an
exterior region of the end fitting 300. Exhaust gas may migrate from the outer annulus
region 319 through the cavity 309 to the passageways. The cavity 309 may be filled
with a resin, in which case a venting conduit could be placed in the cavity prior
to filling with resin, such that the conduit could fluidly connect the outer annulus
region with the passageways.
[0048] An enlarged view of the vent path 318 in the section identified as DETAIL A is shown
in Fig. 4. The vent path 318 additionally includes a valve 322 (a further vent valve)
located at an exit port 323 of the end fitting. The valve 322 is a non-return valve
of a mechanical type that opens when a small pressure difference is created across
the vent valve. This pressure difference may be set at around 2 bar. Accumulated gas
may vent by virtue of an internal pressure being higher than a pressure downstream
of the vent valve. The non-return valve 322 provided in the vent path helps prevent
or inhibit gas from returning to the outer annulus region from the end fitting.
[0049] During operation, accumulated gas in each annular region of the flexible pipe may
be exhausted to a flare system above sea level, for example, via exhaust pathways
external to the end fitting (and not illustrated) which couple to the respective vent
valves. A first pathway is provided by the inner annulus region 312, pathways in the
inner collar 307 and outer collar 308, the tubular conduit 313 and the passageway
314. The passageway 314 may be connected to a tubular conduit to take the exhausted
gas to a flare system or other suitable exit point or collection point. A second pathway
is provided by the outer annulus region 319, the pathway in the jacket 304, the tubular
conduit 320 and the passageway 321. Again, the passageway 321 may be connected to
a tubular conduit to take the exhausted gas to a flare system or other suitable exit
point or collection point.
[0050] The apparatus may be arranged such that gas is completely prevented from mixing between
the annular regions, with each annulus being provided with a separate vent path to
exhaust any accumulating gas. Each vent path also has a non-return vent valve to help
prevent gas from returning to the respective annulus region. However, each or one
of the vent paths could alternatively be provided without a non-return valve.
[0051] Fig.s 3 to 7 illustrate each vent valve 315 and 322 being fully or partially embedded
into the body of the end fitting 300, for instance being inserted into a cavity drilled
into the end fitting body or flange. A vent valve may be recessed or flush with the
surface of the end fitting. It will be appreciated that this is not essential to the
present invention, though may be an arrangement that is desirable in practice, due
to the reduced risk of damage to vent valves. In certain embodiments at least one
vent valve may be provided external to the end fitting.
[0052] According to certain embodiments the vent valve may be arranged to only vent gas
from the pipe body annulus for situations in which the pipe body annulus is purposefully
filled with a fluid, for instance demineralised water including a corrosion inhibitor.
The term "vent plug" may be used interchangeably for "vent valve". As described above,
each vent valve may be coupled to a pipe body annulus via a vent path within the end
fitting.
[0053] Referring now to Fig. 8, in accordance with an embodiment of the present invention
a venting arrangement comprises a manifold 800 in fluid communication with an annular
region of a flexible pipe body. Specifically, the manifold 800 is in fluid communication
with an annular region access port 804 upon or within an end fitting such that the
manifold is in fluid communication with a pipe body annular region (not illustrated
in Fig. 8). The annular region access port 804 may comprise a passageway, lumen or
tube within an end fitting extending to or in fluid communication with a flexible
pipe body annular region. Where the venting arrangement described below is provided
external to the end fitting the or each annular region access port may comprise an
orifice or coupling at an exterior surface of the end fitting suitable to receive
a connecting tube to couple to the manifold. Where the venting arrangement is at least
partially incorporated into the end fitting, the or each annular region access port
may comprise the form of connecting passageway or tube described above which extends
to a pipe body annular region. According to certain embodiments of the present invention
the manifold 800 may be attached to or incorporated into the end fitting itself. The
further components of the venting arrangement may also be incorporated into the end
fitting. The manifold 800 is illustrated coupled to first and second vent valves 806
and an annular region flushing valve 808, which may be a non-return valve. In certain
embodiments there may only be a single vent valve 806 or there may be more than two.
Each vent valve 806 serves to vent gas from the pipe body annular region in the manner
described above in connection with Fig.s 3 to 7. The manifold 800 serves to bring
each valve into fluid communication with the pipe body annular region. The manifold
800 is shown in cross section to reveal an arrangement of passageways 802 which interconnect
each valve. It will be appreciated that the arrangement of passageways within the
manifold may vary according to the respective numbers of vent valves 806 and annular
region flushing valves 808 (in the event that more than one is provided). The manifold
may be configured such that it may be opened to expose the passageways, or it may
be a sealed unit. The passageways 802 are marked A, B, C, and D according to respective
connections to vent valves 806, the annular region flushing valve 808 and the annular
region access port 802, though clearly this arrangement is only exemplary. The annulus
flushing valve 808 serves to periodically flush the annular region access port 804,
which advantageously removes any debris blocking the port 804 or the manifold 800
itself. This prevents blocking and may therefore serve to prolong the life span of
the riser 203 by ensuring pressure does not build up to a point where the outer sheath
of the pipe body is breached by the annulus internal pressure. The annular region
flushing valve 808 may also serve to fill the pipe body annulus with a fluid including
a corrosion inhibitor. The annular region flushing valve 808 may also serve to flush
the interior side of the vent valves 806. Furthermore, the annular region flushing
valve 808 may be used to extract fluid samples from the pipe body annular region for
testing (particularly in the case that the vent valves 806 exhaust gas only). It will
be appreciated that the annular region flushing valve 808 is arranged with respect
to the manifold 800 in an opposite direction to the vent valves 806. That is, whereas
the vent valves serve to vent fluid from the annular region via the annular region
access port 804 when the pressure within the manifold 800 exceeds the pressure on
the other side of the vent valve 806 by a predetermined amount, the annular region
flushing valve serves to admit fluid into the manifold 800 when the pressure outside
of the manifold on the opposite side of the annular region flushing valve 808 exceeds
the pressure within the manifold 800 by a further predetermined amount (which may
be same amount or may differ). The respective valve types suitably comprise non-return
valves acting in opposite directions.
[0054] Advantageously, because the embodiment of the present invention illustrated in Fig.
8 allows for the annular region access port 804 and/or the vent valves (and the manifold)
to be flushed to prevent blocking, the present invention does not require independent
access to the pipe body annulus for each vent valve. This may result in a more streamlined
end fitting. The embodiment of the present invention illustrated in Fig. 8 may be
retrofitted to existing end fittings, if it is configured in a form external to the
end fitting itself) to prolong their life span, even for end fittings with only a
single annular region access port which were hitherto at risk of blocking. Such retrospective
fitting may comprise removing one or more existing vent valves and coupling the connecting
passageway to the manifold 800. It will be appreciated that this may require that
the manifold is configured with more than one connection to annular region access
ports. Alternatively, the manifold may be wholly incorporated into the body of a new
end fitting, with internal or external connections to each vent valve or annulus flushing
valve (or one or more of the valves may also be incorporated into the body of the
end fitting) and inwardly to one or more annular region access ports.
[0055] Furthermore, because in normal operation it may be expected that there will no longer
be a need to replace a vent valve (given that it can be flushed from inside the manifold
to prevent blocking) there is no risk of sea water entering the manifold during replacement
of a vent valve at a sub-sea location.
[0056] The embodiment of the present invention shown in Fig. 8 also provides for dual redundancy
for the vent valves while requiring only a single annular region access port. Each
vent valve operates independently of the other. Preferably, each vent valve is able
to accommodate the maximum anticipated flow of fluid from the pipe body annulus such
that correct operation will continue in the event of total failure of one of the vent
valves. Further redundancy may be provided by substituting a non-return annulus flushing
valve with a valve that also serves to vent fluid from the annulus. It will be appreciated
that this redundancy may be extended by coupling further vent valves to the same manifold.
Redundancy can be increased further by providing multiple manifolds, each connected
to a separate annular region access port within the end fitting or cross coupled to
the or each same annular region access port.
[0057] The manifold 800 may suitably comprise a milled block of steel or corrosion resistant
alloy, suitable for the environment and the pressure requirements of the service in
which it will operate, in which passageways coupling to each valve 806, 808 and the
annular region access port 804 intersect. The manifold may include a removable front
plate for maintenance purposes (sealed with suitable sealing systems), which upon
removal exposes the passageways 802. However, the present invention is not restricted
to any particular form of manifold. Indeed in other embodiments there may be no separate
component identifiable as a manifold in the event for instance that each valve 806,
808 directly accesses or branches off a single annular region access port 804 or a
suitable connecting passageway.
[0058] Fig. 8 further illustrates optional sub-sea isolation valves 810. As each vent valve
806 may operate independently to accommodate fluid flow from the pipe body annular
region, sub-sea isolation valves 810
1 and 810
2 may be provided between each vent valve 806 and the manifold 800, at least for embodiments
of the invention where the manifold 800 is external to the end fitting. Optionally,
the annular region flushing valve 808 may also be coupled to the manifold through
an isolation valve 810, though this is not illustrated in Fig. 8. The manifold 800
itself may be coupled to the annular region access port 804 via an isolation valve
500
3, though again this may not be required or appropriate where the manifold 800 or other
portions of the venting arrangement forms part of the end fitting. Fig. 8 is shown
partially exploded and partially in cross section, which exposes the internal passageways
802 within the manifold 800 and suitable forms of each valve 806, 808, though the
present invention is not limited to the particular valves shown in Fig. 8. Each isolation
valve 810 may be closed to isolate a valve, or the whole manifold, allowing its replacement
in the event of damage or blocking that can't be alleviated through the injection
of a flushing fluid through the annular region flushing valve 808. This allows for
in service vent valve testing and replacement. Furthermore, actuation of the isolation
valves 810 coupled to the vent valves 806 may allow the annular region flushing valve
808 to be used to pressurise the annulus up to the rating of the pipe body where this
is required for maintenance or testing. This allows for in service annulus flushing.
[0059] Referring now to Fig. 9, in accordance with a further embodiment of the present invention
multiple vent valves 806 (two or more, three being illustrated) may be cross coupled
to annular region access ports 804 (two or more, three being illustrated) via separate
cross coupled connecting tubes 600. The connecting tubes 600 comprise lateral flow
tubes interconnected by four-way couplers 602. The arrangement is shown in an open
ended fashion in Fig. 9 such that additional annular region access ports 804 and vent
valves 806 may be provided, but it will be appreciated that at the edges of the system
the four-way couplers 602 may be replaced by three-way couplers. Alternatively, in
a scenario in which annular region access ports 804 are distributed about the periphery
of an end fitting, the lateral flow tubes may be connected in a closed loop. More
generally, the annular region access ports 804 and the vent valves 806 may be cross
coupled in any desired fashion. In the event of a blockage 604 in a first annular
region access port 804 or indeed any portion of a connecting tube extending to an
annular region access port 804, the lateral flow tubes 600 allow a vent valve that
would otherwise cease to operate to be connected to the pipe body annular region as
indicated through arrows 606 through a parallel annular region access port 804. The
arrangement of connecting tubes 600 may be referred to as a connecting harness. Alternative
connection schemes will be readily apparent to the appropriately skilled person.
[0060] As for the embodiment of the invention shown in Fig. 8, the embodiment of Fig. 9
allows for enhanced redundancy in the event of a failure insofar as each vent valve
may still be used in the event of a one or two connecting tubes or annular region
access port blocking, so long as there remains at least vent valve in fluid communication
with the pipe body annular region. This solution may be readily retrofitted to existing
flexible pipe end fittings or incorporated into a modified end fitting, in which case
the necessary couplings may be partially or fully incorporated into the body of the
end fitting itself.
[0061] It will be appreciated that by extension the manifold of Fig. 8 may be cross coupled
to multiple end fitting annular region access ports through a similar arrangement
of connecting harness to that shown in Fig. 9. In such a situation multiple manifolds
may be cross coupled to multiple access ports or a single manifold may have multiple
inwards connections to annular region access ports. Similarly, the use of an annular
region flushing valve may be incorporated into the connecting harness of Fig. 9, thereby
providing the same benefits to the embodiment of Fig. 9: flushing to clear blocked
connecting tubes, vent valves, access ports or manifolds. Also, the vent valves shown
in Fig. 9 may be coupled via isolation valves as for Fig. 8 to allow each vent valve
to be isolated and repaired or replaced.
[0062] It will be clear to a person skilled in the art that features described in relation
to any of the embodiments described above can be applicable interchangeably between
the different embodiments. The embodiments described above are examples to illustrate
various features of the invention.
[0063] Throughout the description and claims of this specification, the words "comprise"
and "contain" and variations of them mean "including but not limited to", and they
are not intended to (and do not) exclude other moieties, additives, components, integers
or steps. Throughout the description and claims of this specification, the singular
encompasses the plural unless the context otherwise requires. In particular, where
the indefinite article is used, the specification is to be understood as contemplating
plurality as well as singularity, unless the context requires otherwise.
[0064] Features, integers, characteristics, compounds, chemical moieties or groups described
in conjunction with a particular aspect, embodiment or example of the invention are
to be understood to be applicable to any other aspect, embodiment or example described
herein unless incompatible therewith. All of the features disclosed in this specification
(including any accompanying claims, abstract and drawings), and/or all of the steps
of any method or process so disclosed, may be combined in any combination, except
combinations where at least some of such features and/or steps are mutually exclusive.
The invention is not restricted to the details of any foregoing embodiments.
1. A vent arrangement for a flexible pipe body, the vent arrangement comprising:
an annular region access port (804) of a flexible pipe end fitting (300);
a vent valve (806) arranged to couple to the region access port (804) such that the
vent valve (806) can vent fluid from the pipe body annular region (312) via the annular
region access port (804); and
an annular region flushing valve (808) arranged to couple to the annular region access
port (804) and in fluid communication with the vent valve (806), the annular region
flushing valve (808) being arranged to inject fluid into the vent arrangement for
flushing the vent valve (806) and the annular region access port (804), and arranged
to inject fluid into the pipe body annular region via the annular region access port
(804) for flushing the pipe body annular region.
2. A vent arrangement according to claim 1, comprising at least two vent valves (806)
coupled together to be in fluid communication with one another and arranged to couple
to the annular region access port (804) such that each vent valve (806) may vent fluid
from the pipe body annular region (312) via the annular region access port (804).
3. A vent arrangement according to claim 1 or claim 2, wherein the vent valve (806) is
arranged to couple to at least two annular region access ports (804) of the flexible
pipe end fitting such that each vent valve (806) may vent fluid from the pipe body
annular region (312) via any coupled annular region access port (804).
4. A vent arrangement according to claim 3 when dependent on claim 2, further comprising
a connecting harness arranged to cross couple the at least two vent valves (806) to
at least the at least two annular region access ports (804) of a flexible pipe end
fitting.
5. A vent arrangement according to any one of the preceding claims, further comprising
a manifold (800) interconnecting each vent valves (806) and annulus flushing valve
(808).
6. A vent arrangement according to any one of the preceding claims, further comprising
at least one isolation valve (810) coupled to a respective vent valve (806) and arranged
to selectively isolate the vent valve (806) or annular region flushing valve (808)
from fluid communication with the remainder of the vent arrangement.
7. An end fitting (300) for a flexible pipe body, the end fitting (300) comprising:
a body (301) arranged to couple to a first flexible pipe body (100), the body (100)
having a bore (302) arranged to be in fluid communication with the bore of the first
flexible pipe body (100) and the body (301) being arranged to couple to a second flexible
pipe body, a further end fitting or flexible pipe terminal equipment;
at least one annular region access port (804) formed within or connected to the body
(301) and arranged to allow fluid communication with an annular region (312) of the
first flexible pipe body (100); and
a vent arrangement according to any one of the preceding claims.
8. An end fitting (300) for a flexible pipe body according to claim 7, wherein the vent
arrangement is coupled to or at least partially incorporated into the body of the
end fitting (300).
9. A flexible pipe comprising an end fitting (300) according to claim 7 or claim 8 and
a flexible pipe body (100) coupled to the end fitting.
10. A method of manufacturing a flexible pipe, the method comprising:
coupling an end fitting (300) for a flexible pipe to a flexible pipe body (100);
wherein the end fitting (300) comprises:
a body (301) arranged to couple to a first flexible pipe body (100), the body (301)
having a bore (302) arranged to be in fluid communication with the bore of the first
flexible pipe body (100) and the body (301) being arranged to couple to a second flexible
pipe body, a further end fitting or flexible pipe terminal equipment;
at least one annular region access port (804) formed within or connected to the body
(301) and arranged to allow fluid communication with an annular region (312) of the
first flexible pipe body (100); and
a vent arrangement comprising:
a vent valve (806) arranged to couple to the annular region access port (804) such
that the vent valve (806) can vent fluid from the pipe body annular region (312) via
the annular region access port (804); and
an annular region flushing valve (808) arranged to couple to the annular region access
port (804) and in fluid communication with the vent valve (806), the annular region
flushing valve (808) being arranged to inject fluid into the vent arrangement for
flushing the vent valve (806) and the annular region access port (04), and arranged
to inject fluid into the pipe body annular region (312) via the annular region access
port (804) for flushing the pipe body annular region (312).
1. Entlüftungsanordnung für einen flexiblen Rohrkörper, wobei die Entlüftungsanordnung
umfasst: einen Ringbereichszugangsanschluss (804) eines Endstücks (300) eines flexiblen
Rohrs;
ein Entlüftungsventil (806), das angeordnet ist, um mit dem Ringbereichszugangsanschluss
(804) so zu koppeln, dass das Entlüftungsventil (806) Fluid aus dem Rohrkörperringbereich
(312) über den Ringbereichszugangsanschluss (804) entlüften kann; und
ein Ringbereichsspülventil (808), das angeordnet ist, um mit dem Ringbereichszugangsanschluss
(804) und in Fluidverbindung mit dem Entlüftungsventil (806) zu koppeln, wobei das
Ringbereichsspülventil (808) angeordnet ist, um Fluid in die Entlüftungsanordnung
zum Spülen des Entlüftungsventils (806) und des Ringbereichszugangsanschlusses (804)
zu injizieren, und angeordnet ist, um Fluid in den Rohrkörperringbereich über den
Ringbereichszugangsanschluss (804) zum Spülen des Rohrkörperringbereichs zu injizieren.
2. Entlüftungsanordnung nach Anspruch 1, umfassend mindestens zwei Entlüftungsventile
(806), die miteinander gekoppelt sind, um in Fluidverbindung miteinander zu stehen,
und angeordnet sind, um mit dem Ringbereichszugangsanschluss (804) so zu koppeln,
dass jedes Entlüftungsventil (806) Fluid aus dem Rohrkörperringbereich (312) über
den Ringbereichszugangsanschluss (804) entlüften kann.
3. Entlüftungsanordnung nach Anspruch 1 oder Anspruch 2, wobei das Entlüftungsventil
(806) angeordnet ist, um mit mindestens zwei Ringbereichszugangsanschlüsse (804) des
Endstücks des flexiblen Rohrs so zu koppeln, dass jedes Entlüftungsventil (806) Fluid
vom Rohrkörperringbereich (312) über einen gekoppelten Ringbereichszugangsanschluss
(804) entlüften kann.
4. Entlüftungsanordnung nach Anspruch 3, wenn von Anspruch 2 abhängig, ferner umfassend
einen Verbindungskabelbaum, der angeordnet ist, um die mindestens zwei Entlüftungsventile
(806) mit mindestens den mindestens zwei Ringbereichszugangsanschlüssen (804) eines
Endstücks des flexiblen Rohrs über Kreuz zu koppeln.
5. Entlüftungsanordnung nach einem der vorhergehenden Ansprüche, ferner umfassend einen
Verteiler (800), der jedes Entlüftungsventil (806) und ein Ringspülventil (808) miteinander
verbindet.
6. Entlüftungsanordnung nach einem der vorhergehenden Ansprüche, ferner umfassend mindestens
ein Absperrventil (810), das mit einem jeweiligen Entlüftungsventil (806) gekoppelt
ist und angeordnet ist, um das Entlüftungsventil (806) oder das Ringbereichsspülventil
(808) selektiv von der Fluidverbindung mit dem Rest der Entlüftungsanordnung zu isolieren.
7. Endstück (300) für einen flexiblen Rohrkörper, wobei das Endstück (300) umfasst:
einen Körper (301), der angeordnet ist, um mit einem ersten flexiblen Rohrkörper (100)
zu koppeln, wobei der Körper (100) eine Bohrung (302) aufweist, die angeordnet ist,
um in Fluidverbindung mit der Bohrung des ersten flexiblen Rohrkörpers (100) zu sein,
und der Körper (301) angeordnet ist, um mit einem zweiten flexiblen Rohrkörper, einem
weiteren Endstück oder einer Anschlussausrüstung für ein flexibles Rohr zu koppeln;
mindestens einen Ringbereichszugangsanschluss (804), der innerhalb des Körpers (301)
ausgebildet oder mit diesem verbunden ist und angeordnet ist, um eine Fluidverbindung
mit einem ringförmigen Bereich (312) des ersten flexiblen Rohrkörpers (100) zu ermöglichen;
und
eine Entlüftungsanordnung nach einem der vorhergehenden Ansprüche.
8. Endstück (300) für einen flexiblen Rohrkörper nach Anspruch 7, wobei die Entlüftungsanordnung
mit dem Körper des Endstücks (300) gekoppelt oder zumindest teilweise in diesen eingearbeitet
ist.
9. Flexibles Rohr, umfassend ein Endstück (300) nach Anspruch 7 oder Anspruch 8 und einen
flexiblen Rohrkörper (100), der mit dem Endstück verbunden ist.
10. Verfahren zur Herstellung eines flexiblen Rohrs, wobei das Verfahren umfasst: Koppeln
eines Endstücks (300) für ein flexibles Rohr mit einem flexiblen Rohrkörper (100);
wobei das Endstück (300) umfasst:
einen Körper (301), der angeordnet ist, um mit einem ersten flexiblen Rohrkörper (100)
zu koppeln, wobei der Körper (301) eine Bohrung (302) aufweist, die angeordnet ist,
um in Fluidverbindung mit der Bohrung des ersten flexiblen Rohrkörpers (100) zu sein,
und der Körper (301) angeordnet ist, um mit einem zweiten flexiblen Rohrkörper, einem
weiteren Endstück oder einer Anschlussausrüstung für ein flexibles Rohr zu koppeln;
mindestens einen Ringbereichszugangsanschluss (804), der innerhalb des Körpers (301)
ausgebildet oder mit diesem verbunden ist und angeordnet ist, um eine Fluidverbindung
mit einem ringförmigen Bereich (312) des ersten flexiblen Rohrkörpers (100) zu ermöglichen;
und eine Entlüftungsanordnung, die umfasst:
ein Entlüftungsventil (806), das angeordnet ist, um mit dem Ringbereichszugangsanschluss
(804) so zu koppeln, dass das Entlüftungsventil (806) Fluid aus dem Rohrkörperringbereich
(312) über den Ringbereichszugangsanschluss (804) entlüften kann; und ein Ringbereichsspülventil
(808), das angeordnet ist, um mit dem Ringbereichszugangsanschluss (804) und in Fluidverbindung
mit dem Entlüftungsventil (806) zu koppeln, wobei das Ringbereichsspülventil (808)
angeordnet ist, um Fluid in die Entlüftungsanordnung zum Spülen des Entlüftungsventils
(806) und des Ringbereichszugangsanschlusses (04) zu injizieren, und angeordnet ist,
um Fluid in den Rohrkörperringbereich (312) über den Ringbereichszugangsanschluss
(804) zum Spülen des Rohrkörperringbereichs (312) zu injizieren.
1. Agencement d'évent destiné à un corps de tuyau flexible, l'agencement d'évent comprenant
: un orifice d'accès de zone annulaire (804) d'un raccord d'extrémité de tuyau flexible
(300) ;
une soupape d'évent (806) agencée pour être couplée à l'orifice d'accès de zone annulaire
(804) de sorte que la soupape d'évent (806) puisse évacuer le fluide de la zone annulaire
de corps de tuyau (312) par l'intermédiaire de l'orifice d'accès de zone annulaire
(804) ; et
une soupape de rinçage de zone annulaire (808) agencée pour se coupler à l'orifice
d'accès de zone annulaire (804) et en communication fluidique avec la soupape d'évent
(806), la soupape de rinçage de zone annulaire (808) étant agencée pour injecter du
fluide dans l'agencement d'évent en vue du rinçage de la soupape d'évent (806) et
de l'orifice d'accès de zone annulaire (804), et agencée pour injecter du fluide dans
la zone annulaire de corps de tuyau par l'intermédiaire de l'orifice d'accès de zone
annulaire (804) en vue du rinçage de la zone annulaire de corps de tuyau.
2. Agencement d'évent selon la revendication 1, comprenant au moins deux soupapes d'évent
(806) couplées l'une à l'autre pour être en communication fluidique l'une avec l'autre
et agencées pour être couplées à l'orifice d'accès de zone annulaire (804) de sorte
que chaque soupape d'évent (806) puisse évacuer le fluide provenant de la zone annulaire
de corps de tuyau (312) par l'intermédiaire de l'orifice d'accès de zone annulaire
(804).
3. Agencement d'évent selon la revendication 1 ou 2, ladite soupape d'évent (806) étant
agencée pour être couplée à au moins deux orifices d'accès de zone annulaire (804)
du raccord d'extrémité de tuyau flexible de sorte que chaque soupape d'évent (806)
puisse évacuer le fluide de la zone annulaire de corps de tuyau (312) par l'intermédiaire
de n'importe quel orifice d'accès de zone annulaire couplé (804).
4. Agencement d'évent selon la revendication 3 lorsqu'elle dépend de la revendication
2, comprenant en outre un faisceau de raccord agencé pour coupler transversalement
les au moins deux soupapes d'évent (806) à au moins les au moins deux orifices d'accès
de zone annulaire (804) d'un raccord d'extrémité de tuyau flexible.
5. Agencement d'évent selon l'une quelconque des revendications précédentes, comprenant
en outre un collecteur (800) reliant chaque soupape d'évent (806) et une soupape de
rinçage annulaire (808).
6. Agencement d'évent selon l'une quelconque des revendications précédentes, comprenant
en outre au moins une soupape d'isolement (810) couplée à une soupape d'évent respective
(806) et agencée pour isoler sélectivement la soupape d'évent (806) ou la soupape
de rinçage de zone annulaire (808) de la communication fluidique avec le reste de
l'agencement d'évent.
7. Raccord d'extrémité (300) pour un corps de tuyau flexible, le raccord d'extrémité
(300) comprenant :
un corps (301) agencé pour être couplé à un premier corps de tuyau flexible (100),
le corps (100) possédant un alésage (302) agencé pour être en communication fluidique
avec l'alésage du premier corps de tuyau flexible (100) et le corps (301) étant agencé
pour être couplé à un second corps de tuyau flexible, à un équipement terminal de
tuyau flexible ou un raccord d'extrémité supplémentaires ;
au moins un orifice d'accès de zone annulaire (804) formé à l'intérieur du corps (301)
ou raccordé à celui-ci et agencé pour permettre une communication fluidique avec une
zone annulaire (312) du premier corps de tuyau flexible (100) ; et
un agencement d'évent selon l'une quelconque des revendications précédentes.
8. Raccord d'extrémité (300) destiné à un corps de tuyau flexible selon la revendication
7, ledit agencement d'évent étant couplé au corps du raccord d'extrémité (300) ou
au moins partiellement incorporé à celui-ci.
9. Tuyau flexible comprenant un raccord d'extrémité (300) selon la revendication 7 ou
8 et un corps de tuyau flexible (100) couplé au raccord d'extrémité.
10. Procédé de fabrication d'un tuyau flexible, le procédé comprenant : le couplage d'un
raccord d'extrémité (300) pour un tuyau flexible à un corps de tuyau flexible (100)
; ledit raccord d'extrémité (300) comprenant :
un corps (301) agencé pour être couplé à un premier corps de tuyau flexible (100),
le corps (301) possédant un alésage (302) agencé pour être en communication fluidique
avec l'alésage du premier corps de tuyau flexible (100) et le corps (301) étant agencé
pour être couplé à un second corps de tuyau flexible, à un équipement terminal de
tuyau flexible ou un raccord d'extrémité supplémentaires ;
au moins un orifice d'accès de zone annulaire (804) formé à l'intérieur du corps (301)
ou raccordé à celui-ci et agencé pour permettre une communication fluidique avec une
zone annulaire (312) du premier corps de tuyau flexible (100) ; et un agencement d'évent
comprenant :
une soupape d'évent (806) agencée pour être couplée à l'orifice d'accès de zone annulaire
(804) de sorte que la soupape d'évent (806) puisse évacuer le fluide de la zone annulaire
de corps de tuyau (312) par l'intermédiaire de l'orifice d'accès de zone annulaire
(804) ; et une soupape de rinçage de zone annulaire (808) agencée pour se coupler
à l'orifice d'accès de zone annulaire (804) et en communication fluidique avec la
soupape d'évent (806), la soupape de rinçage de zone annulaire (808) étant agencée
pour injecter du fluide dans l'agencement d'évent en vue du rinçage de la soupape
d'évent (806) et de l'orifice d'accès de zone annulaire (04), et agencée pour injecter
du fluide dans la zone annulaire de corps de tuyau (312) par l'intermédiaire de l'orifice
d'accès de zone annulaire (804) en vue du rinçage de la zone annulaire de corps de
tuyau (312).